1. Field of the Invention
The invention relates to detergent packets, in particular detergent packets including liquid detergent contained within a water soluble pouch.
Liquid detergent is used in the field of laundry, glass, floor and carpet cleaning. Consumers widely accept the packaging of liquid detergent in pre-measured amounts known as unit doses because of its convenience. Consumers have a tendency to use more detergent than sufficient or necessary, thus the unit dose detergent packaging prevents over-consumption and is more environmentally-friendly.
When liquid detergent is packed in a pouch, the pouch must be dissolved in water for the liquid detergent to be used for cleaning objects. Consumers have demanded higher cleaning performance from liquid detergent. As a result, different active ingredients have been combined in liquids detergents to achieve higher performance. Some kinds of active ingredients may chemically react with one another when mixed. In order to prevent this chemical reaction, a separation packaging in a pouch may be employed.
Liquid detergents may contain glycols as a diluent. In order to reduce costs, liquid detergent manufacturers have begun using water as a diluent. Water soluble pouches, however, do not have resistance against high water contents. In particular, water soluble pouches by their nature dissolve in cold water. The dissolution of a water soluble pouch packed with a liquid detergent having a high water content descends with time. Moreover, the surface of a water soluble pouch packed with a liquid detergent having a high water content will become sticky. Accordingly, it has previously been difficult or impossible to provide a water soluble pouch containing a high water content liquid detergent having acceptable performance properties.
2. The Prior Art
U.S. Pat. No. 5,341,932 to Chen et al. relates to hazardous materials containing water with various ions but does not disclose a liquid detergent packaging or specific limitation for each salt concentration in the formulation. Chen et al. also fails to disclose the advantageous effect of adding sulfate on the deterioration of a water soluble pouch when it is dissolved in water. U.S. Pat. No. 7,271,141 to Kaiser et al. relates to water soluble packages containing polyphosphate builder and special ratios of potassium to sodium ions. A detergent packet according to an embodiment of the invention does not require potassium ions or a special ratio of potassium to sodium ions.
U.S. Pat. No. 7,557,075 to Fregonese et al. relates to water soluble package with a liquid detergent containing a high volume water content, a polyphosphate builder material and Sorbitol. Fregonese et al. does not mention sulfate salts or the advantageous effect of adding sulfate on the deterioration of a water soluble pouch when it is dissolved in water. U.S. Pat. No. 5,253,759 to Gouge et al. relates to a water soluble bag in bag arrangement for agrochemicals packaging wherein the bag in bag arrangement prevents the interaction of chemicals by separating. Gouge et al. does not disclose a detergent packaging or high water content packed chemicals.
U.S. Pat. No. 6,632,785 to Pfeiffer at al. relates to water soluble sachet packed gel form detergents and high volume of water. Pfeiffer at al. does not disclose a liquid detergent packaging, specific limitations for each salt concentration in the formulation or the advantageous effects of adding sulfate on the deterioration of a water soluble pouch when it is dissolved in water. U.S. Pat. No. 7,642,226 to Verrall at al. relates to a water soluble co-polymer film packed a liquid detergent and film thickness range. U.S. Pat. No. 6,787,512 to Verrall at al. relates to a water soluble co-polymer film containing a unit dose of liquid detergent. The Verrall at al. patents do not mention a liquid detergent containing water.